One-step algae harvesting, dewatering, FAME production
Researchers from the University of Texas at Austin have developed a proof-of-concept design to harvest, dewater and convert algae to biodiesel in a one-step process using resins. In a paper titled, “Use of Anion Exchange Resins for One-Step Processing of Algae from Harvest to Biofuel,” University of Texas at Austin scientists Jessica Jones, Cheng-Han Lee, James Wang and Martin Poenie note that to circumvent the cost-prohibitive obtainment of algae oil due to the pumping and processing of large volumes of dilute algal suspensions, they used Amberlite anion exchange resins to simplify the process, which has potential to greatly reduce costs. Researchers packed a column with the beaded, fixed-charge Amberlite anion exchange resins and poured dilute algae water through. The algae bind with the resins and, at the point of saturation, the water coming out of the bottom of the column changed from clear to green-colored. They eluted algae off the resins with a 5 percent mix of methanol and sulfuric acid, essentially regenerating the resins for reuse. “The eluted algae appear to dissolve in the sulfuric acid reagent and esterified fatty acids are converted to FAMEs (biodiesel),” the researchers note. Poenie tells Biodiesel Magazine the researchers are working to develop resins with higher binding capacities.